But a new research paper raises some questions about whether mandatory arrests in every case is the right approach. It’s possible arresting an alleged abuser may be really bad for some victims’ long-term health.

A follow-up of a study done 23 years ago found that that domestic violence victims whose partners were arrested on misdemeanor charges (when no injuries resulted) were more likely to have died than those whose partners were merely warned by police. These were not the people who died because of an attack, but rather those who died years later of health-related reasons, including heart disease, cancer or other internal disorders. Somehow, the study suggests, the emotional toll of having a partner arrested messed up their health in the years afterwards.

Interestingly, the study was conducted by the same guy whose research was largely responsible for the introduction of the mandatory arrest provisions in the first place, Lawrence Sherman, now the Director of the Institute of Criminology of the University of Cambridge. “Changing your position in democracies has gotten very difficult,” says Sherman. “But as John Maynard Keynes said: when my information changes, I alter my conclusions.” Sherman has got some support from law enforcement circles.

What Sherman originally found, in a study done in Minneapolis, was that mandatory arrests in misdemeanor cases lowered future domestic violence rates. Those who were arrested were less likely to abuse again. At the time, the late 70s, intimate partner violence was largely considered a domestic issue and not an area for police intervention. Sherman’s study, which got enormous publicity, was part of turning that understanding around.

The problem was, Sherman was never able to replicate the results. In fact, in Milwaukee and other cities that had a high concentration of poor minorities living in segregated neighborhoods, the results were in fact the opposite. Now, having followed up on Milwaukee a quarter of a century later with the help of Heather Harris, a doctoral student at the University of Maryland, he believes mandatory arrests do less then no good, they do actual harm to the victims’ long term health.

For African-Americans, who were in the majority of victims in the original study, the figures were particularly stark. Black women whose partners were arrested on domestic violence charges were nearly twice as likely to have died of ill-health by 2013 than women whose husbands/partners were accused of domestic violence but were not arrested. (In white victims, the difference was only 9%). Even more puzzlingly, the research found that black victims who were employed when their partners were arrested, suffered a death rate more than four times higher than those whose partners were just warned. For white victims, employment status made no difference.

It’s not clear what biological mechanism is causing the early death in these victims. Mostly, those who were arrested were held overnight, so it’s not the strain of a long-incarcerated spouse that loused up their health. And many of those arrested were not employed, so it’s not the loss of income, either. These were misdemeanor arrests, meaning the abuser had probably not physically injured the victim. The main distinction between the victims who had died by the time of the second study and those who didn’t, was that they saw their partners get cuffed.

“We are now sure that the difference in death was not due to homicide, which was our original research question,” says Sherman. The authors believe similar mechanisms to those in Post Traumatic Stress Disorder (PTSD) might be at fault. “The racial difference suggests that the best explanation must be bio-social,” says Sherman. “There must be something about witnessing a partner’s arrest that triggers a physiological response leading to higher rates of death from heart disease and other internal maladies, but far more so for victims who are African-American than for whites.”

Sherman believes that because Milwaukee was (and still is) a very segregated city, and white women tended to live in more affluent areas, the partner arrest was less traumatic for them. Usually, if the white women were employed, they were not the primary breadwinners. Somehow, observing the arrest of their spouse or partner had a less negative impact on their identities. “The social world of concentrated and segregated poverty areas, where most of the African-American victims lived, was very different from the social world of the white victims,” says Sherman. “Something about that difference appears to have combined with arrest to double the death rate for Blacks. That combination was even more deadly if the black victims had a job, and perhaps had much more fear about losing respect as a result of the partner’s arrest.”

The analysis involved a records search on the 1125 participants in the original Milwaukee Domestic Violence Experiment, which took place between 1987 and 1988. During that study, police randomly arrested two thirds of the suspects of domestic violence and merely warned one third. Fewer than 5% of them were ever prosecuted. The records indicated that 91 victims had subsequently died; 70 of them were in the arrest group and 21 in the warning-only group.

The findings were released on March 3 and will be published in an upcoming issue of the Journal of Experimental Criminology. If they can be repeated and hold true, they raise very real questions about how to balance the need to protect people from intimate partner violence in the short term, while keeping an eye on their longer term health. Other studies have also called the mandatory arrest policy into question. For his part, Sherman is in favor of fewer arrests. “We need to look at many other alternatives to arrest that may better ensure the immediate goal of protecting the safety of victims, but without the heavy hand (and potential stigma) of the criminal justice system,” he says.

Police could be given more discretion to discern whether a situation calls for an arrest or another approach, although similar situations have sometime led to victims being murdered. Alcohol abuse treatments might be more beneficial to the accused abuser’s families. Sherman points to the work of New York University academic and domestic violence victim Linda Mills on restorative justice conferences for victims, families and offenders’ families.

The findings have been criticized by Domestic Victims’ advocates, who say it’s not appropriate to apply old data to the situation today. “Thankfully for victims of domestic violence, we don’t live in the 1980s anymore,” representatives with End Domestic Abuse Wisconsin said in a written statement. “Twenty-five-year-old data cannot be used to conclude that domestic violence arrests are dangerous to victims.”

But Milwaukee police chief Edward Flynn thinks it might be time to try a new approach, only in the case of misdemeanors, noting that awareness of the gravity of domestic violence is now much greater. “We have to ask: Is the criminal justice system the best place to deal with domestic violence misdemeanors?” he says. “It might be time for a thoughtful dispassionate reassessment of these procedures.” Sherman added that in most cases the arrests do not result in an indictment because the victim rarely shows up in court, but that the arrests stay on the record.

“The well-intentioned efforts to help victims must be judged by their results, not our intentions,” says Sherman. “Thus what we need to do is to treat domestic violence as a subject for relentless research, testing a wide range of solutions, rather than simply assuming that punishment “works.””